TODO

 - "locale"
 - real regerror
 - improve code size and quality with __restrict__.
 - FPU exception handling (for mawk)
 - res_mkquery should not assume op is QUERY
 - syslog
 - gethost/netent -> parselib?
 - Look at qsort (the make test suite exhibits the worst case)
 - Make __dtostr do scientific notation.
 - fix %g in printf.  They are more or less completely b0rken (in
   particular rounding the last digit does not work).
 - qmail-queue dumps core since we added vfork.  Editing fork.h to #define
   vfork to fork works.  What happens here?
 - use TCP if buf[2]&2 is non-zero in DNS answers.
 - look at mktime: "Falls tm_isdst == -1 gesetzt, so sollte mktime
   versuchen herauszufinden, ob Sommerzeit eingestellt ist (und laut linux
   manpage auch tzname setzen), ansonsten die angegebene DST
   berücksichtigen."
 - better rand()?
 - try to make zebra compile.
 - printf %e
 - move DNS stuff to libresolv.a?
 - x86_64: readdir fails their test (Gwenole Beauchesne)
 - regular expressions standards compliance; test suite from AT&T
 - fgetpwent (needed for cvm)
 - investigate putting some libgcc symbols in dietlibc.so for gcc<3
 - wordexp, wordfree (might as well write a /bin/sh then)

implement AI_V4MAPPED in getaddrinfo (not in man page, only susv3)

Also: AF_UNSPEC, AI_ADDRCONFIG
set_thread_area -> set up TLD, for stack guard

lsearch, lfind, hsearch, tsearch

getopt configure check fails:

  {
    char *argv[3] = { "program", "-ab", NULL };
    optind = OPTIND_MIN;
    opterr = 0;
    if (getopt (2, argv, "ab:") != 'a')
      return 13;
    if (getopt (2, argv, "ab:") != '?')
      return 14;	/* fails here */
    if (optopt != 'b')
      return 15;
    if (optind != 2)
      return 16;
  }